Connecting strip ends in making tube



' June 2, 1942.. z 2,285,209

CONNECTING STR'IP ENDS IN MAKING TUBE Filed Feb. 12, 1940 3 Sheets-Sheet l iNVENTOR. K773? Ar arafi lol BY June 2, 1942. LKA'rz 2,285,209

CONNECTING STRIP Ems IN MAKING TUBE Filed Feb. 12, 1940' :5 Shegts-Sheet 2 June 2, 1942. A. KATZ 2,235,209

CONNECTING STRIP ,END S IN MAKING'TUBE- I Filed Feb. 12, 1940 3 Sheets-Sheet 3 INVENTOR.

strip through the tube rolling machine.

the machine.

tion of the apparatus.

strip.

Patented June 2, 1942 CONNECTING STRIP ENDS IN MAKING TUBE Albert Katz, Detroit, 1Mich., assignor to Tubing Company, tion of Michigan Bundy Detroit, .Mich., .a corpora- Application February 12, 1940, Serial No. 318,584

7 Claims.

This invention relates to the making of tubing from strip stock where the strip is moved longitudinally through a tube forming apparatus, and it has to do particularly with the making of tube with a double ply wall.

i he strip stock from which tubing is made is usually supplied in rolls or coils containing say from 500 to 1000 feet of strip, depending upon the .size of the coil and the dimensions, includingthe thickness of the strip. When the forward end of such a strip is passed through a tube mill,

the first -1ew feet of tubing is wasted because it is not properly supported. Similarly, the last few feet of the trailing end of the strip is wasted.

Thus several feet of tubing is wasted for each coil of strip. Moreover, there is an appreciable loss of time in threading the forward end of each This latter item is particularly undesirable with tube forming machiner which propels the strip forward rather rapidly, say in excess of 100 ieetper minute, sincethe efforts which are expended in themaking of a rapidly operating tube mill are defeated, to a large extent, because every few' minutes a new strip has to be threaded through This invention relates particularly to the provision of an'arrangement for uniting the trailing end of one strip to the forward end of the next succeeding strip so that a multiplicity of strips may be fed through the tube forming machinery in susccession and without a break in the opera- Several difierent ways of doing this have been proposed, as for example, by

welding thestrip ends together, but this requires relatively large expensive equipment and considerable labor, and the joint has to be ground to eliminate any burr or thrown up excess metal, and to reduce the seam to the thicknessof the The present invention provides an arrangement for uniting the ends of the strips which can bedonequickly and without expensive equipment. It will be appreciated that such a joint,

if it embodies overlapping stock such as to produce an undesirable extra thickness in the tube wall at the location of the joint, will put an undue load on the forming apparatus, with the re--' sult that the forming apparatus may be damaged or broken. For example, if a single strip be fashioned to form a double ply wall to provide a tube structure of the nature of thatshown in the Bert L. Quarnstrom Patent No. 2,014,983 of 7 .September 17, 1935, and if the strip ends are.

overlapped at the joint of connection the wall of the tube at this point will have a thickness of four plies. Notwithstanding this, however, the present invention provides an arrangement where the joint or connection between the ends of the strips can be made with an overlapping arrangement with the ends held together b spot weld connections or the like, and the arrangement is such that when the tube is formed, there is, at no place, a tube wall thickness which exceeds the normal thickness of the double ply wall tube.

With this arrangement only a few inches of the finished-tube need be cut away as wasted for the purpose of removing the section of finished tube at the joint between the strips. The invention will be better understood as the detailed description progresses in conjunction with the accompanying drawings.

Fig. 1 is a rather diagrammatic view of a tube forming apparatus showing two coils of strip.

Fig. 2 is an enlarged cross sectional view taken substantially on line 22 of Fig. 1 showing the strip.

Fig. 3 is a cross sectional View taken substantially on line 33 of Fig. 1 showing the finished tube.

Fig. 4 Ban enlarged View showing the respective trailing and forward ends of two strips of stock.

Fig. 5 is a view similar to Fig. 4 showing the ends of the strips connected.

Fig, 6 ma cross sectional view taken substantially on line 5-4; of Fig. 5.

Fig. 7 is a view similar to Fig. 6 showing a first step in the formation of the tube.

Fig. 8 is a cross sectional view showing a second step in the formation of the tube.

Fig. 9 is a view showing a third step in the formation of the tube.

Fig. 10 is a cross sectional view of the finished tube taken through the joint.

Fig. 11 is a plan view illustrating a modified form of the invention and showing a modifiedarrangernentof the ends of the strips.

Fig. 12 shows the strip ends of Fig. 11 connected together. i

Fig. 13 is across sectional view teikensubstantially on line [3-13 of Fig. 12.

Fig. 14 is a cross sectional view of the finished tube of the modified form taken through the joint a further form of the invention.

Fig. 16 is a cross sectional view taken substan- -tially=on line iii-Jfiof Fig. 15.

Fig. 17 is a cross sectional view through a joint fashioned in the manner shown in Figs. 15 and 16.

Fig. 18 is a view of strip ends showing a still further modified form of the invention.

Fig. 19 is a view similar to Fig. 18 showing the strip ends connected.

Fig. 20 is a view taken on line Eli-Z3 of Fig, 19.

Fig. 21 is a cross sectional view of a tube and taken through a joint constructed after the manner shown in Figs. 18, 19 and 20.

Fig. 22 is an enlarged View of the joint illustrated in Fig. 21 and illustrating, in dotted lines, the normal seam of the tube.

The tube mill shown in Fig. 1 more or less diagrammatically, has a set of forming rolls generally illustrated at I through which the strip is passed, and fashioned into tube. The strip may be fashioned around an arbor 2 supported as at 3. The strip in the mill is indicated at A, the same being supplied from a coil as shown, while the next succeeding strip is shown at B. In the making of a tube of the form shown in Fig. 3, the edges of the strip are preferably beveled as indicated in Fig. 2, by rollers 4, and when the tube is fashioned by the forming of it through substantially 720 the edges lap over an intermediate offset. The tube is shown as an outer ply and an inner ply 6, while the edges seat against the offset 1. It will be understood that the seam at the edges and offset and the plies may be and preferably are secured together as by means of the application of a molten sealing metal, such as hard or soft solder or otherwise.

Now the present invention is devoted to the connecting of the trailing end of the strip A to the leading end of the strip B, and, of course, also to the trailing end of all strips and the leading ends of all succeeding strips. It will be understood that the ends of a number of coils may thus be united and the coils located at a mill for.

use, so that the mill can operate over a long period of time without stopping.

In Fig. 4 the trailing end of the strip A is cut to form a notch Ill, leaving projections at the edges of the strip as shown at H and. |2. leading edge of the strip B is similarly cut to form a notch l3 andprojections l4 and [5. The two ends are then placed together as shown in Fig. 5, with the projections I! and I4 overlapping and with the projections l2 and I5 overlapping, and leaving an opening Ill. The overlapping projections may be spot welded together as indicated at is. As indicated in Figs. 5 and 6, the projection l4 underlies projection I I, while at the opposite side of the strip, the arrangement is reversed, with the projection l5 of the strip B overlying |2 of the strip A. When the joint between the ends passes between the beveling rollers 4, the edges are beveled as shown in Fig. 6.

In the fashioning of the strip into tube, the double ply formations at the overlapping projections are caused to lie in the opening l0" and thus the tube wall at the location of the joint has the normal tube wall thickness. The tubemay be fashioned after the manner illustrate-d in Figs. '7, 8 and 9. The strip may be fashioned with more or less of a rolling action starting from the right hand side as shown in Fig. 7, and then into the Fig. 8 position where it will be seen that the double wall formation H-M begins to come into the opening III". In Fig. 9 the double wall formation ||-|4 lies in a part of the opening while the double wall formation |2-|5 is in position to enter the other part of the open- ThiS ing, and Fig. 10 shows the complete tube formation. The beveled edges come together at IT,

.while the metal defining the ends of the opening ll) meet in the manner of a butt seam as at l8.

Thus, although the stock is overlapped at the ends, the finished tube at the joint has only the normal double wall thickness, and the joint will pass through the mill without placing an undue load on the rollers and. arbor or other forming apparatus. The portion Id of the strip B forms a part of the outer ply, while the portion I5 ultimately becomes a part of the inner ply. This is the reason for the reversing of the overlap as shown in Figs. 5 and 6. This form of the invention is preferred because the joint secures the ends of the strips together adjacent the edges thereof, and thus not only provides an unbroken edge, but gives the joint greater strength than in some of the succeeding forms to be described.

In the modified form shown in Figs. 11 to 14, the strips are again referred to as strips A and B. The trailing end of strip A is cut to provide a central projection 20, while strip B is cut to form one projecting edge 2!, and when the two are overlapped as shown in Fig. 12, there is an opening 22 at one edge and a double thickness only at the overlap'between portions of the parts 2%! and 2|, as illustrated at 23, and these parts may be spot welded together as indicated.

The lapping parts of the projecting portions 20 and 2! are arranged so that the portion 2| underlies the portion 20. When this joint is fashioned into tube the opening or notch 22 constitutes half the circumference of the inner ply; half of the part 2!] constitutes the other half of the inner ply, while the second half of the part it lies in the notch 22; thus in a sense, the portion 2f] constitutes the complete inner ply at the joint. The portion 2| constitutes the entire outer ply at this point, all as shown in Fig. 14. The opposite edges of the projection 2|] come together in a sort of a butt joint as at 24, while the opposite edges of projection meet in a butt seam as at 24'.

In Figs. 15 and 16, the strips A and B are similarly formed, but the part 2| overlies the part 23'. In this case, as shown in Fig. 17, about onehalf of the portion 26 constitutes a part of the inner ply and then jogs outwardly as at 25 so that the other half part constitutes part of the outer ply, whereas the projection 2| constitutes a part of the outer ply and then jogs inwardly as at 26 to constitute a part of the inner ply.

A further modification is shown in Figs. 18 and 19 where the strip A has a centrally disposed projection 30 and the strip B has a centrally disposed projection 3| provided with a slot 32. The part 30 is placed in the slot by means of an offset formed therein as at 33 so that part of the projection 3|] lies above 3| and a part lies below as indicated in Fig. 20. This construction leaves an opening 35 and an opening 33. In the formed tube, as shown in Fig. 21, that portion of the projection 30 which is uppermost as shown in Fig. 20 forms part of the inner ply and that portion which is lowermost forms part of the outer ply, while the part of the portion 3| which is lowermost, as shown in Fig. 20, forms a part of the outer ply and lies in the opening 36, and the part which is uppermost forms part of the inner ply and lies in the opening 35. It will be understood that this joint structure is very small in axial extent, that is, axially of the tube, and to clarify the arrangement there is shown in Fig. 22 a joint at 33, and then in dotted lines the regular joint of the tube. As shown in Fig, 20, the parts of the projection 3| on opposite sides of the slot 32 are in substantial alignment, whereas in the finished tube they are disaligned as shown in Fig. 21. This is due to the pressure of the forming rolls which forces the metal into its final shape.

As heretofore explained the form shown in Figs. 4 and 5 is preferred because the connected strips present unbroken edges, while in the other forms the notches are exposed at the edges. The continuous edge makes for better passage of the strip through the tube mill and also, the two ends may be formed with the same tool. In all forms, however, the notch or opening formation accommodates the double thickness of the joint between the strips.

In some of the claims appended hereto reference is made to the fact that the receding portions form an opening; this is to be construed to cover the form shown in Figs. 4 and 5 where there is in fact a single opening Ill", and the form shown in Figs. 11 and 12 where there is a single opening 22, as well also as the form shown in Figs. 18 and 19 where there are two openings and 36.

I claim:

1. In the making of tube from strip metal stock wherein the stock is moved longitudinally and fashioned into tube with a wall of double thick- I ness having inner and outer plies, the method of joining the trailing end and the leading end of successive strips which comprises fashioning said ends with relatively longitudinally projecting and receding parts, overlapping the project- :1

ing parts, securing the overlapping parts together, thereby forming a double stock thickness at the overlap, with the relatively receding parts forming an opening, fashioning the strip stock into double ply tube with an overlapping part 11 lying in the opening whereby the wall at the joint between the two ends is of a double thickness and substantially the same as the thickness of the tube wall.

2. In the making of tube from strip metal stock wherein the stock is moved longitudinally and fashioned into tube having a plural ply wall of substantially uniform thickness, the method of joining the trailing end and the'leading end of successive strips which comprises, fashioning the ends with relatively longitudinally projecting and receding parts, overlapping the projecting parts,

thereby forming a section of double thickness at the overlap and securing the overlapping parts together, the receding parts forming an opening, fashioning the strip stock into tube with a plural ply wall, with the double thickness at the overlapping parts accommodated and lying in part in the opening, whereby the wall thickness at the joint is of plural ply formation corresponding to the thickness of the tube wall.

3. In the making of tube from strip metal stock wherein the stock is moved longitudinally and fashioned into tube with a wall of double thickness having inner and outer plies, the method of joining the trailing end and the leading end of successive strips which comprises iashioning said ends with relatively projecting and receding parts, overlapping the projecting parts, securing the overlapping parts together, thereby forming a double stock thickness at the overlap, with the relatively receding parts forming an opening, the opening having an extent transversely of the strip,

at last equal to the transverse extent of the overlap, fashioning the strip into double ply tube and placing an overlapping part in the opening whereby the wall at the joint is of the two-ply thickness corresponding to that of the tube wall.

4. In the making of tube from strip metal stock wherein a single strip is moved lengthwise and fashioned into tube with a wall of double thickness having inner and outer plies, the method of joining the trailing end and the leading end of successive strips which comprises, fashioning said ends of the strip with relatively projecting and receding parts, overlapping the projecting parts and securing them together, thereand fashioned into tube with a wall of double thickness having inner and outer plies, the method of joining the trailing end and the leading end of successive strips which comprises, fashioning said ends with centrally, disposed recesses, leaving projecting parts at the edges, overlapping said parts and securing them together with the receding parts cooperating to form an opening, fashioning the strip into double ply tube with one of the parts at each overlap lying in the openingwhereby the wall at the joint is of the double thickness corresponding to that of the tube.

6. A joint structure'between the trailing and leading ends of strip metal stock fashioned into double ply tubing comprising, projecting parts adjacent the edges of the trailing and leading ends and a receding part in the central portion of the trailing and leading ends, the projecting parts being disposed in overlapping relationship and united together with the receding portions forming an opening, the opening having an extent, transversely of the tube, at least equal to the combined transverse extent of the overlapping parts, one of the projecting parts of each overlap lying within the opening whereby the wall of the tube structure at double-ply thickness.

7. A joint structure between the trailing and leading ends of strip metal stock fashioned into double ply tube which comprises, projecting and the joint is of the receding portions on the trailing and leading ends, the projecting portions extending longitudinally of the strip stock, so that the edges of i the trailing and leading ends are of irregular shape, the projecting portions being disposed in overlapping relationship and united together,

ALBERT KATZ. 

